A sloped wall structure of the type to extend from the upper surface of a straight wall in an upwardly sloped direction to the vertical surface of a parapet wall assembly usually is formed with a plurality of rafters extending in parallel spaced relationship with respect to one another and purlins extending laterally across the rafters with glass panes or other sheets of infill material extending between the rafters and purlins. The rafters are the main load-bearing members of the sloped wall structure, and the rafters not only support their own weight but also the weight of the horizontal purlins, sheet infill and any external loads placed on the sloped wall structure such as wind forces, rain, snow, ice, etc.
The rafters of a sloped wall structure usually are assembled first at the building site. When the rafters are installed, it is not uncommon that the expected angle of the wall is slightly different than what was planned by the builder. For example, if the sloped wall was planned for 30.degree. from the horizontal, it is not unusual that the wall is finally installed at anywhere from 28.degree. to 32.degree. from the horizontal. If the rafters are anchored at both their upper and lower ends to the supporting surfaces of the lower straight wall and upper parapet wall, the support structures for the rafters must be specially fabricated and/or installed to accomodate the particular final angle of slope of the wall structure.
The usual load bearing connector structure for connecting and supporting the rafters from their lower and upper support surfaces comprises a plurality of anchor clips, one anchor clip being provided at each end of each rafter and rigidly connecting the rafter to the supporting surfaces. The anchor clip usually comprises a base plate that rests flat on and attaches to the support structure and a leg rigidly extending from the base plate and formed at an angle with respect to the base plate which corresponds to the angle of slope of the rafter. Connecting screws connect the leg of the anchor clip to the rafter.
The prior art structures utilized prefabricated anchor clips which are fabricated of one piece construction with a fixed angle between the base plate and the leg, so that the angle formed between the leg and the base plate cannot be altered. Because of this inflexibility of the anchor clip, builders have formed their anchor clips and rafters so that certain construction tolerances exist between them and so that the builder can accomodate variations in the expected slope of the wall structure without requiring a modification of the components. For example, the rafters can be formed with multiple connector openings so that anchor clips can be connected to various ones of the connector openings to support the rafters at different attitudes. In instances where the actual slope of the wall is beyond or between tolerances formed in the rafter structure or in the anchor clip, the builder is required to make further modifications to the structure to accomodate the particular actual slope of the wall structure, or to have special parts made to accomodate the varying slope of the wall structure.
While builders can work with the tolerances provided in particular components of a wall structure to accomodate slight variations in the angle of the wall structure, the same anchor clips cannot be used to install one wall structure with a slope of 30.degree. from the horizontal and another wall structure that is 45.degree. or 60.degree. from the horizontal. Different anchor clips are required for variations of this type or, in the alternative, the holes punched in the ends of the rafters would have to be positioned differently to accomodate the leg of the anchor clip in a different position with respect to the rafter.
The prior art sloped wall structures use fabrication and installation techniques at the upper portion of each rafter that requires another anchor clip which is different from the anchor clip at the base of the wall structure. This creates the need for different structures at the upper and lower ends of each rafter to accommodate wall structures of different slopes.